Internal and external are all the same essence.

This means that when we are practicing, the mountains and rivers of the great earth, the sun, the moon, the stars, and the constellations, the internal body and the external world, as well as all dharmas, are all viewed as being the same essence of the true mind.

Dharma Master Seng-chao said, “Heaven and earth and I have the same root. The myriad things and I have the same essence.”

Jinul (1158 CE-1210 CE), Jinul Puril Bojo Daesa, often called Jinul or Chinul for short, was a Korean monk of the Goryeo period, who is considered to be the most influential figure in the formation of Korean Seon (Zen) Buddhism.